[Bug] Aria label for series-custom is displayed in wrong language

[alexjcook]

Version

5.4.1

Link to Minimal Reproduction

https://echarts.apache.org/examples/en/editor.html?c=custom-bar-trend

Steps to Reproduce

1. Visit the echarts example for Custom Bar Trend:
   https://echarts.apache.org/examples/en/editor.html?c=custom-bar-trend
2. Toggle "Decal Pattern" to true (which automatically sets aria.label.enabled to true)
3. Use firefox accessibility tab to view the generated aria description for the chart

Current Behavior

The generated aria description starts with
"This is a chart. It consists of 8 series count. The 0 series is a 自定义图 representing trend."

Expected Behavior

The aria description should be generated in the user's local language.
"This is a chart. It consists of 8 series count. The 0 series is a custom series representing trend."

Environment

- OS: Windows 10
- Browser: Firefox 107, 64-bit
- Framework: N/A

Any additional comments?

Ideally for a custom series we could define our own aria description to describe what is rendered, instead of "custom".
For the above example the custom series is rendered as a line, so it would be great if we could configure an aria-related option on the series so the following description could be generated
"This is a chart. It consists of 8 series count. The 0 series is a line representing trend."

[plainheart]

@Ovilia It seems the fallback series type name is hard-coded as 自定义图. It should be able to be translated in each locale file.
https://github.com/apache/echarts/blob/master/src/visual/aria.ts#L267